Power amplification apparatus and television signal transmission system

ABSTRACT

An amplification unit contains two or more sets containing a plurality of amplification circuits, and amplifies power of an RF (Radio Frequency) signal. A combining unit contains two or more combiners corresponding to the two or more sets, combines RF signals output by the amplification circuits, and outputs a resultant RF signal. The amplification unit and the combining unit have two or more connectors which are arranged transversely. The amplification unit and the combining unit are attachable/detachable.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 16/237,196, filed on Dec. 31, 2018, which is aDivisional of U.S. patent application Ser. No. 15/744,561, filed on Jan.12, 2018, issued Jul. 23, 2019, as U.S. Pat. No. 10,361,661, which is aNational Stage of International Application No. PCT/JP2015/004447, filedon Sep. 1, 2015, the contents of all of which are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present invention relates to a power amplification apparatusamplifying the power of RF (Radio Frequency) signals and a televisionsignal transmission system having such a power amplification apparatus.

BACKGROUND ART

Patent Document 1 describes a power amplifier for use in poweramplification of RF signals. The power amplifier described in PatentDocument 1 is provided with a plurality of sets of a first amplificationunit and a second amplification unit, in which a Doherty combiner isprovided in each set. Furthermore, the power amplifier described inPatent Document 1 is provided with a broadband combiner combining outputsignals of the Doherty combiners. In a first amplification unit, aplurality of amplification circuits operating in Class AB or Class B isprovided in parallel and a combiner combining output signals of theamplification circuits is further provided. In a second amplificationunit, a plurality of amplification circuits operating in Class C isprovided in parallel and a combiner combining output signals of theamplification circuits is further provided. In the power amplifierdescribed in Patent Document 1, each first amplification unit, eachsecond amplification unit, each Doherty combiner, and the broadbandcombiner are stored in a different chassis and the Doherty combiner canbe exchanged.

In the power amplifier described in Patent Document 1, the firstamplification units and the second amplification units are arranged inthe vertical direction as illustrated in FIG. 5 of Patent Document 1. Inthe Doherty combiner corresponding to the set of the first amplificationunit and the second amplification unit, two input connectors into whichRF signals are input are disposed in such a manner as to be arranged inthe longitudinal direction. The first amplification unit and the secondamplification unit each have one output connector. The output connectorof the first amplification unit disposed on the upper side is connectedto the input connector on the upper side in the Doherty combiner and theoutput connector of the second amplification unit disposed on the lowerside is connected to the input connector on the lower side in theDoherty combiner.

Patent Document 2 describes a solidified shortwave band transmissionsystem of several tens of kW class. The solidified shortwave bandtransmission system described in Patent Document 2 has a combining unitcontaining a plurality of pre-combiner and one post-combiner. Moreover,a plurality of power amplifiers which can be individually detached andattached is provided in each pre-combiner. Each pre-combiner combinesoutputs of the plurality of power amplifiers and the post-combinercombines outputs of the plurality of pre-combiners.

Patent Document 3 describes a configuration in which a plurality ofamplification units is disposed between a distributor and a combiner.The amplification unit described in Patent Document 3 is one obtained byintegrating a plurality (for example, 8) of individual selectionamplifiers as one unit. When an individual selection amplifier is added,the individual selection amplifier is added in terms of amplificationunit.

Patent Document 4 describes a power combining apparatus having aplurality of band pass filters having mutually different pass bands andone or two or more circulators. The power combining apparatus describedin Patent Document 4 has a configuration in which a first band passfilter and a second band pass filter are connected with a firstcirculator and an n-th (n is natural number.) circulator and an n+2-thband pass filter are successively connected through with an n+1-thcirculator.

A television broadcasting organization obtains approval of undertakingthe broadcasting industry by transmitting television signals using thefrequency band obtained by dividing the UHF (Ultra High Frequency) band(470 to 862 MHz) or the VHF (Very High Frequency) band (170 to 230 MHz)by a fixed bandwidth as the unit. For example, a broadcastingorganization using the UHF band obtains approval of undertaking thebroadcasting industry using the frequency band obtained by dividing theUHF band by a 8 MHz bandwidth as the unit. Depending on countries, thebandwidth dividing the UHF band is sometimes 6 MHz or 7 MHz.

CITATION LIST Patent Literature

PTL 1: International Publication No. WO2014/155512

PTL 2: Japanese Unexamined Patent Publication Application No. 11-41117

PTL 3: Japanese Unexamined Patent Publication Application No. 9-200105

PTL 4: Japanese Unexamined Patent Publication Application No.2004-140445

SUMMARY OF INVENTION Technical Problem

As an example of the configuration of a common power amplificationapparatus for use in a television signal transmission system, theconfiguration illustrated in FIG. 17 is considered. A common poweramplification apparatus 90 illustrated in FIG. 17 is an integratedapparatus having a plurality of amplification circuits 91, a pluralityof pre-combiners 92, and a post-combiner 93. FIG. 17 illustrates a casewhere six amplification circuits 91 and two pre-combiners 92 areprovided. To each pre-combiner 92, three amplification circuits 91 areconnected. Each amplification circuit 91 amplifies the power of an RFsignal to be input, and then outputs the resultant RF signal to thepre-combiners 92. Each pre-combiner 92 combines RF signals output by thethree amplification circuits 91, and then outputs the resultant signalto the post-combiner 93. The post-combiner 93 combines the RF signalsoutput by the two pre-combiners 92, and then outputs the resultant RFsignal to a device on the latter stage (which is not illustrated in FIG.17) of the power amplification apparatus 90. The RF signal is a signalto be transmitted as a television signal.

The power amplification apparatus 90 illustrated in FIG. 17 combines RFsignals output from the plurality of amplification circuits 91, and thenoutputs the resultant RF signal. Therefore, the number of an output end94 of the RF signals is one. In the power amplification apparatus 90illustrated in FIG. 17, the pre-combiners 92 and the post-combiner 93are disposed in the center, and the signal output end of eachamplification circuit 91 is directed to the center side (pre-combiner 92side) of the power amplification apparatus 90. Therefore, the directionof the signal output end of each amplification circuit 91 and thedirection of the output end 94 of the power amplification apparatus 90are different from each other.

Each amplification circuit 91 amplifies the power of broadband RFsignals. For example, each amplification circuit 91 is an amplificationcircuit usable for the entire UHF band or the entire VHF band. On theother hand, in the power amplification apparatus 90, the component(particularly pre-combiner 92) for the combination of RF signalscombines RF signals of a specific frequency band. More specifically, thecomponent (particularly pre-combiner 92) for the signal combination inthe power amplification apparatus 90 combines RF signals of a frequencyband for which a broadcasting organization has obtained approval.

A manufacturer manufacturing the power amplification apparatus 90manufactures the power amplification apparatus 90 for each broadcastingorganization according to the frequency band for which a broadcastingorganization has obtained approval. However, the amplification circuit91 amplifies the power of broadband RF signals, and therefore it ispreferable for a manufacturer that the component (group of amplificationcircuits 91) for the power amplification of RF signals of the poweramplification apparatus 90 can be manufactured in a standardized mannerirrespective of broadcasting organizations, and then can provided toeach broadcasting organization.

Moreover, a broadcasting organization obtains approval of thebroadcasting industry for a plurality of kinds of frequency bands insome cases. In this case, the broadcasting organization uses the poweramplification apparatus 90 illustrated in FIG. 17 for each frequencyband for which a broadcasting organization has obtained approval. Thecommon power amplification apparatus 90 illustrated in FIG. 17 is anintegrated apparatus. Therefore, when the amplification circuit 91breaks down, the entire power amplification apparatus 90 needs to beexchanged. When it is supposed that the component (set of amplificationcircuits 91) for the power amplification of RF signals of the poweramplification apparatus 90 is standardized irrespective of broadcastingorganizations, and is separable from the component for signalcombination, even when the amplification circuit 91 of any poweramplification apparatus 90 among a plurality of kinds of the poweramplification apparatus 90 breaks down, only a portion equivalent to thecomponent for power amplification may be exchanged. However, the commonpower amplification apparatus 90 illustrated in FIG. 17 is an integratedapparatus, and therefore it is impossible to exchange only a portionequivalent to the component about power amplification.

Furthermore, even when the component for signal combination breaks down,it is impossible to exchange only a portion equivalent to the componentfor a signal combination in the integrated power amplification apparatus90 illustrated in FIG. 17.

Therefore, when a portion equivalent to the component (set ofamplification circuits 91) for power amplification of RF signals of thepower amplification apparatus 90 can be standardized, so that thecomponent (set of amplification circuits 91) for power amplification andthe component for signal combination can be separately manufactured, itis preferable also for manufacturers of a power amplification apparatusand also for broadcasting organizations obtaining approval of thebroadcasting industry of a plurality of kinds of frequency bands.

Moreover, in the power amplifier described in Patent Document 1, theoutput connector of the first amplification unit disposed on the upperside is connected to the input connector on the upper side in theDoherty combiner and the output connector of the second amplificationunit disposed on the lower side is connected to the input connector onthe lower side the Doherty combiner as described above (refer to FIG. 5of Patent Document 1). The first amplification unit, the secondamplification unit, the Doherty combiner, and the like described inPatent Document 1 are accommodated in a rack. Since a device on thelatter stage side is generally accommodated in a deep side of the rack,the Doherty combiner is accommodated in the deep side of the rack andthe first amplification unit and the second amplification unit areaccommodated on the front side of the rack. Then, when the Dohertycombiner breaks down, the Doherty combiner cannot be taken out from therack only by removing only one of the first amplification unit on theupper stage and the second amplification unit on the lower stage fromthe Doherty combiner. In order to take out the Doherty combiner from therack, there is a necessity of removing both the first amplification unitand the second amplification unit from the Doherty combiner. In order tofacilitate the exchange of the broken Doherty combiner, it is preferablethat the Doherty combiner can be taken out only by removing one device.

Then, it is an object of the present invention to provide a poweramplification apparatus which enables separation of a component forpower amplification of RF signals and a component for combination of RFsignals and enables easy exchange of a component for combination of RFsignals and a television signal transmission system having the poweramplification apparatus.

Solution to Problem

A power amplification apparatus according to the present invention hasan amplification unit containing at least one set containing apredetermined number of amplification circuits amplifying the power ofan RF (Radio Frequency) signal and a combining unit containing acombiner provided corresponding to the set and combining RF signalsoutput by the amplification circuits belonging to the corresponding set,and then outputting the resultant RF signal, in which the amplificationunit has an output connector for outputting the RF signal output by theamplification circuit for each amplification circuit, the outputconnectors are arranged in the horizontal direction, the combining unithas an input connector into which the RF signal output from the outputconnector of the amplification unit is input for each output connector,the input connectors are arranged in the horizontal direction, theamplification unit and the combining unit are attachable/detachablethrough the output connectors and the input connectors, and the surfaceon which the input connectors are provided of the combining unit is setwithin the dimension of the surface on which the output connectors areprovided of the amplification unit.

A television signal transmission system according to the presentinvention has the above-described power amplification apparatus.

Advantageous Effects of Invention

According to the present invention, a component for power amplificationof RF signals and a component for combination of RF signals can beseparated from each other, so that the component for combination of RFsignals can be easily exchanged.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view illustrating an example of a poweramplification apparatus of a first embodiment of the present invention.

FIG. 2 is a side view of the power amplification apparatus.

FIG. 3 is a perspective view of the power amplification apparatus.

FIG. 4 is a perspective view in connecting an amplification unit and acombining unit.

FIG. 5 is a schematic view illustrating an example of the configurationof the combining unit.

FIG. 6 is a flow chart illustrating an example of processing progress ofthe power amplification apparatus of the first embodiment of the presentinvention.

FIG. 7 is a schematic view illustrating a state where a plurality ofpower amplification apparatuses is disposed.

FIG. 8 is a schematic view illustrating an example of the poweramplification apparatus when two amplification circuits 2 are set as oneset.

FIG. 9 is a schematic view illustrating an example of a poweramplification apparatus of a second embodiment of the present invention.

FIG. 10 is a schematic view illustrating a state where an amplificationunit and a combining unit are connected to each other.

FIG. 11 is a flow chart illustrating an example of processing progressof the power amplification apparatus of the second embodiment of thepresent invention.

FIG. 12 is an explanatory view illustrating an example of anamplification unit in which output connectors 3 arranged in thetransverse direction are disposed in two stages.

FIG. 13 is a block diagram illustrating an example of the configurationof a television signal transmission system of a third embodiment of thepresent invention.

FIG. 14 is a flow chart illustrating an example of processing progressof the television signal transmission system.

FIG. 15 is a block diagram illustrating an example of a televisionsignal transmission system having one power amplification apparatus.

FIG. 16 is a block diagram illustrating the outline of the poweramplification apparatus of the present invention.

FIG. 17 is a schematic view illustrating an example of the configurationof a common power amplification apparatus.

DESCRIPTION OF EMBODIMENT

Hereinafter, embodiments of the present invention are described withreference to the drawings.

Embodiment 1

FIG. 1 is a schematic view illustrating an example of a poweramplification apparatus of a first embodiment of the present invention.The power amplification apparatus 10 of this embodiment has anamplification unit 1 and a combining unit 5. FIG. 1 illustrates a statewhere the amplification unit 1 and the combining unit 5 are notconnected

The amplification unit 1 has a plurality of amplification circuits 2.FIG. 1 is a top view and schematically illustrates the arrangementpositions of the amplification circuits 2 in the amplification unit 1when the power amplification apparatus 10 is viewed from above. However,each amplification circuit 2 is stored in a chassis of the amplificationunit 1 and cannot be seen from the outside in actual.

In the amplification unit 1, at least one set containing a predeterminednumber of amplification circuits 2 is provided. The first embodimentdescribes a case where a plurality of sets of the amplification circuits2 is provided. FIG. 1 illustrates a case where three amplificationcircuits 2 are set as one set and two sets of the amplification circuits2 are provided. The number of the sets of the amplification circuits 2provided in the amplification unit 1 may be three or more.

Each amplification circuit 2 amplifies the power of an input RF signal,and then outputs the RF signal after power amplification. The RF signalis a signal transmitted as a television signal.

Each amplification circuit 2 is realized by an FET (Field EffectTransistor), for example. Hereinafter, a description is given taking acase where each amplification circuit 2 is realized by an FET as anexample.

The amplification unit 1 has an output connector 3 for outputting an RFsignal output by the amplification circuit 2 for each amplificationcircuit 2. Therefore, the amplification circuits 2 and the outputconnectors 3 are in one-to-one correspondence. The output connectors 3are disposed so as to be arranged in the horizontal direction on a sidesurface 11 facing the combining unit 5 among the side surfaces of theamplification unit 1. The amplification circuits 2 are disposed so thatthe signal output end of the amplification circuit 2 faces thecorresponding output connector 3. Then, each output connector 3 isconnected to the signal output end of the corresponding amplificationcircuit 2 and outputs an RF signal output by the correspondingamplification circuit 2 as it is. Accordingly, when focusing on onearbitrary output connector 3, the output connector 3 outputs an RFsignal output by the corresponding one amplification circuit 2 as it is.Therefore, a circuit combining the RF signals output by theamplification circuits 2 is not contained in the amplification unit 1.

Moreover, the combining unit 5 has an input connector 6 into which an RFsignal output from the output connector 3 is input for each outputconnector 3. Therefore, the output connectors 3 of the amplificationunit 1 and the input connectors 6 of the combining unit 5 are inone-to-one correspondence. Accordingly, it can be said that theamplification circuits 2 and the input connectors 6 are also inone-to-one correspondence. The input connectors 6 are disposed so as tobe arranged in the horizontal direction on a side surface 51 facing theamplification unit 1 among the side surfaces of the combining unit 5.

The output connectors 3 arranged in the horizontal direction in theamplification unit 1 and the input connectors 6 arranged in thehorizontal direction in the combining unit 5 are disposed so that outputconnectors 3 and the input connectors 6 corresponding to each other aresimultaneously connected to each other. For example, the outputconnectors 3 and the input connectors 6 are disposed so that theinterval between the central axes of the output connectors 3 adjacent toeach other and the interval between the central axes of the inputconnector 6 adjacent to each other are equal to each other.

Therefore, the amplification unit 1 and the combining unit 5 areattachable/detachable through the output connectors 3 and the inputconnectors 6. By simultaneously connecting the output connectors 3 andthe input connectors 6 corresponding to each other, the amplificationunit 1 and the combining unit 5 are brought into a connection state. Inthe example illustrated in FIG. 1, the amplification unit 1 and thecombining unit 5 are brought into a connection state by simultaneouslyconnecting six output connectors 3 and six input connectors 6.

Each input connector 6 is a floating connector.

The output connectors 3 and the input connectors 6 are coaxialconnectors. In the state where the output connectors 3 and the inputconnectors 6 are connected to each other, RF signals output by theamplification circuits 2 are input into the combining unit 5 through theoutput connectors 3 and the input connectors 6. The combining unit 5combines the RF signals input from the input connectors 6, and thenoutputs the RF signal after the combination from the output end 9. Theoutput end 9 is provided on the side surface opposite to the sidesurface 51 on which the input connectors 6 are disposed in the combiningunit 5. The configuration of the combining unit 5 is described later.

Next, the relationship between the side surface 11 on which the outputconnectors 3 are disposed of the amplification unit 1 and the sidesurface 51 on which the input connectors 6 are disposed of the combiningunit 5 is described. FIG. 2 is a side view of the power amplificationapparatus 10. FIG. 3 is a perspective view of the power amplificationapparatus 10. FIG. 4 is a perspective view in connecting theamplification unit 1 and the combining unit 5. The same components asthe components illustrated in FIG. 1 are designated by the samereference numerals as those in FIG. 1. The width of the width of theside surface 51 of the combining unit 5 is equal to or lower than thewidth of the width of the side surface 11 of the amplification unit 1.More specifically, when the width of the width of the side surface 11 ofthe amplification unit 1 is set as W1 and the width of the width of theside surface 51 of the combining unit 5 is set as W2 (refer to FIG. 1and FIG. 3), W2 W1 is established. Furthermore, the height of the sidesurface 51 of the combining unit 5 is equal to or lower than the heightof the side surface 11 of the amplification unit 1. More specifically,when the height of the side surface 11 of the amplification unit 1 isset as H1 and the height of the side surface 51 of the combining unit 5is set as H2 (refer to FIG. 2 and FIG. 3), H2 H1 is established.Therefore, the side surface 51 on which the input connectors 6 aredisposed of the combining unit 5 is set within the dimension of the sidesurface 11 on which the output connectors 3 are disposed of theamplification unit 1. The output connectors 3 and the input connectors 6are disposed so that the side surface 51 does not project from the rangeof the side surface 11 in the state where the amplification unit 1 andthe combining unit 5 are connected to each other. As a result, asillustrated in FIG. 4, the side surface 51 does not project from therange of the side surface 11 in the state where the amplification unit 1and the combining unit 5 are connected to each other.

FIG. 5 is a schematic view illustrating an example of the configurationof the combining unit 5. FIG. 5 illustrates a state where theamplification unit 1 and the combining unit 5 illustrated in FIG. 1 areconnected to each other. In the example illustrated in FIG. 5, as aresult of connecting the output connectors 3 and the input connectors 6,each output connector 3 is present in the corresponding input connector6. The combiners 7 are provided in the combining unit 5 corresponding tothe sets of the amplification circuits 2 provided in the amplificationunit 1. In the first embodiment, two or more of the sets of theamplification circuits 2 are present, and therefore the combining unit 5has two or more of the combiners 7. In the example illustrated in FIG.5, three amplification circuits 2 are set as one set and two sets ofsets of the amplification circuits 2 are provided in the amplificationunit 1, and therefore two combiners 7 are provided in the combining unit5.

The combiners 7 are connected to the input connectors 6 corresponding tothe amplification circuits 2 belonging to the set corresponding to thecombiners 7. In other words, the input connectors 6 corresponding to theamplification circuits 2 are connected to the combiners 7 correspondingto the set (set of amplification circuits 2) to which the amplificationcircuits 2 belong. Into the combiner 7, an RF signal output from eachamplification circuit 2 belonging to the set corresponding to thecombiner 7 is input. The combiner 7 combines the RF signals, and thenoutputs the RF signal after the combination. In this example, RF signalsoutput from the three amplification circuits 2 belonging to the setcorresponding to the combiner 7 are input into the combiner 7.

In the present invention, when the combining unit 5 has two or more ofthe combiners 7, the combining unit 5 has one more combiner 8. In thefirst embodiment, the combining unit 5 has the plurality of combiners 7,and therefore further has one combiner 8. Hereinafter, in order todistinguish the combiner 7 and the combiner 8 from each other, thecombiner 7 is referred to as a first combiner 7 and the combiner 8 isreferred to as a second combiner 8. The second combiner 8 combines RFsignals output from the first combiners 7, and then outputs the RFsignal after the combination from the output end 9. The RF signal outputfrom the output end 9 is transmitted to a device on the latter stage ofthe power amplification apparatus 10.

The frequency band of an RF signal which can be amplified by eachamplification circuit 2 is a broadband. For example, each amplificationcircuit 2 is an amplification circuit usable for the entire UHF band orthe entire VHF band.

On the other hand, the first combiner 7 is a combiner usable for RFsignals of a specific frequency band. In other words, the first combiner7 is a combiner limited in the frequency band of RF signals which can becombined. The first combiner 7 combines RF signals of a frequency bandfor which a television broadcasting organization using the poweramplification apparatus 10 has obtained approval. As already describedabove, a broadcasting organization obtains approval of undertaking thebroadcasting industry using the frequency band obtained by dividing theUHF band or the VHF band by a fixed bandwidth as the unit. The firstcombiner 7 is designed so as to be able to combine RF signals of thefrequency band for which a broadcasting organization has obtainedapproval.

As the first combiner 7, a Doherty combiner may be used, for example.The Doherty combiner is a combiner combining an RF signal output by amain amplifier which always performs an amplification operation of an RFsignal (hereinafter referred to as a main amplifier) and an RF signaloutput by a peak amplifier which operates when outputting high power(hereinafter referred to as peak amplifier). Hereinafter, a descriptionis given taking a case where the first combiners 7 illustrated in FIG. 5are all the Doherty combiners as an example.

The Doherty combiner has a transmission line (for example, copper plate)(not illustrated) and can adjust the frequency band of RF signals whichcan be combined based on the length of the transmission line. In themanufacturing of the first combiner 7, the frequency band of RF signalswhich can be combined is adjusted according to the frequency band forwhich a broadcasting organization using the power amplificationapparatus 10 has obtained approval.

When using the Doherty combiner as the first combiner 7, the set (set ofamplification circuits 2) corresponding to the first combiner 7 containsthe amplification circuit 2 equivalent to the main amplifier and theamplification circuit 2 equivalent to the peak amplifier. Hereinafter,the amplification circuit equivalent to the main amplifier is designatedby a reference numeral 2 a and the amplification circuit equivalent tothe peak amplifier is designated by a reference numeral 2 b. In thepower amplification apparatus 10 illustrated in FIG. 1 to FIG. 5, one ofthe three amplification circuits 2 contained in one set is theamplification circuit 2 a equivalent to the main amplifier and theremaining two amplification circuits 2 are the amplification circuits 2b equivalent to the peak amplifier.

It can be changed based on the setting to the amplification circuit 2whether the amplification circuit 2 is used as the main amplifier orused as the peak amplifier. Specifically, it can be determined based ona manner of applying a bias voltage to the amplification circuit 2whether the amplification circuit 2 is used as the main amplifier or thepeak amplifier.

A bias voltage may be applied to the amplification circuit 2 a to beoperated as the main amplifier so as to operate in Class AB or Class B.

A bias voltage may be applied to the amplification circuit 2 b to beoperated as the peak amplifier so as to operate in Class C.

As a result, each first combiner 7 combines an RF signal output by theone amplification circuit 2 a which is set so as to operate in Class ABor Class B and RF signals output by the two amplification circuits 2 bwhich are set so as to operate in Class C.

The second combiner 8 may be a combiner which can combine broadband RFsignals. For example, the second combiner 8 may be a combiner capable ofcombining RF signals of the entire UHF band or the entire VHF band. Forexample, a 3-dB coupler may be used as the second combiner 8.

A Wilkinson combiner may be used as the second combiner 8.

Next, processing progress of the power amplification apparatus 10 isdescribed. FIG. 6 is a flow chart illustrating an example of theprocessing progress of the power amplification apparatus 10 of the firstembodiment of the present invention. The output connectors 3 and theinput connectors 6 corresponding to each other are simultaneouslyconnected to each other, so that the amplification unit 1 and thecombining unit 5 are in a connection state. The power amplificationapparatus 10 is in an operation state.

RF signals are input into the one amplification circuit 2 a and the twoamplification circuits 2 b forming a set. The frequency band of the RFsignals is set within the frequency band for which a broadcastingorganization using the power amplification apparatus 10 has obtainedapproval. The amplification circuit 2 a operates as the main amplifierand the amplification circuits 2 b operates as the peak amplifier. Theamplification circuits 2 a and 2 b output RF signals after poweramplification to the first combiner 7 corresponding to the set.

Each set of the amplification circuits 2 similarly operates (Step S1).In Step S1, each amplification circuit 2 outputs the RF signal afterpower amplification to the first combiner 7 corresponding to the set towhich the amplification circuits 2 belong through the output connectors3 and the input connectors 6 connected to each other.

Each first combiner 7 combines RF signals output from the oneamplification circuit 2 a and the two amplification circuits 2 bbelonging to the corresponding set, and then outputs the RF signal afterthe combination to the second combiner 8 (Step S2).

The second combiner 8 combines the RF signal output from each firstcombiner 7, and then outputs the RF signal after the combination fromthe output end 9 (Step S3). The RF signal output from the output end 9is transmitted to a device on the latter stage of the poweramplification apparatus 10.

According to this embodiment, the amplification unit 1 and the combiningunit 5 are attachable/detachable through the output connectors 3 and theinput connectors 6. Therefore, the component for power amplification ofRF signals and the component for combination of RF signals can beseparated from each other. Specifically, the amplification unit 1 andthe combining unit 5 can be separated from each other.

Therefore, a manufacturer manufacturing the power amplificationapparatus 10 can manufacture the amplification unit 1 in a standardizedmanner irrespective of broadcasting organizations.

It is supposed that a broadcasting organization has obtained approval ofthe broadcasting industry for a plurality of kinds of frequency bands,and uses the power amplification apparatus 10 different for eachfrequency band for which a broadcasting organization has obtainedapproval. The amplification units 1 of the power amplificationapparatuses 10 are standardized irrespective of the frequency bands.Therefore, when the broadcasting organization has a spare amplificationunit 1, the broadcasting organization can exchange the amplificationunit 1 in which a failure has occurred by the spare amplification unit 1even when the failure has occurred in the amplification unit 1 of anypower amplification apparatus 10, and thus can quickly restore the poweramplification apparatus 10.

As described above, the broadcasting organization obtains approval ofundertaking the broadcasting industry using the frequency band obtainedby dividing the UHF band or the VHF band by a fixed bandwidth as theunit. The first combiner 7 is designed so as to be able to combine RFsignals of the frequency band for which a broadcasting organization hasobtained approval. According to the present invention, the amplificationunit 1 does not contain a circuit combining RF signals output by theamplification circuits 2. When the amplification unit 1 and thecombining unit 5 are connected to each other, the first combiner 7 cancombine RF signals of the frequency band for which a broadcastingorganization has obtained approval. More specifically, the frequencybandwidth of RF signals which can be combined by the first combiner 7can be appropriately determined.

The amplification unit 1 does not contain a circuit combining RF signalsoutput by the amplification circuits 2. The output connectors 3 outputsRF signals output by the corresponding amplification circuits 2 as theyare in the shortest distance. Therefore, the passing loss in theamplification unit 1 can be suppressed, so that the power consumptionefficiency can be increased.

Moreover, by the use of the Doherty combiner as the first combiner 7,the power consumption efficiency in power amplification of RF signalscan be improved. When the Doherty combiner is used, the powerconsumption efficiency in power amplification of RF signals can beimproved by setting the plurality of amplification circuits 2 outputtingRF signals to the Doherty combiner as the main amplifier or the peakamplifier and using the Doherty combiner which is optimally adjustedbased on the frequency to be used. Furthermore, a reduction in powerconsumption can be realized due to the improvement of the powerconsumption efficiency in power amplification.

The power amplification apparatus 10 is accommodated in a rack to beused. Since the device on the latter stage side is generallyaccommodated in the back side of the rack as described above, thecombining unit 5 is disposed on the deep side relative to theamplification unit 1 in the rack. In the present invention, theamplification unit 1 has the output connectors 3 arranged in thetransverse direction and the combining unit 5 has the input connectors 6arranged in the transverse direction. Then, by connecting the outputconnectors 3 and the input connectors 6, the amplification unit 1 andthe combining unit 5 are brought into a connection state. Furthermore,the side surface 51 on which the input connectors 6 are disposed of thecombining unit 5 is set within the dimension of the side surface 11 onwhich the output connectors 3 are disposed of the amplification unit 1.Therefore, when the combining unit 5 breaks down, an operator can alsotake out the combining unit 5 when removing the one amplification unit 1connected to the combining unit 5, and thus can easily exchange thecombining unit 5.

The power amplification apparatus 10 is applied to a television signaltransmission system described in a third embodiment described later. Atthis time, only the one power amplification apparatus 10 may be used ortwo or more of the power amplification apparatuses 10 may be used. FIG.7 is a schematic view illustrating a state where the plurality of poweramplification apparatuses 10 is disposed. When the plurality of poweramplification apparatuses 10 is used, the plurality of poweramplification apparatuses 10 is disposed in a plurality of stages in thevertical direction in a rack (not illustrated). FIG. 7 illustrates astate where three power amplification apparatuses 10 are disposed inup-and-down information in three stages. For example, it is supposedthat the combining unit 5 of the power amplification apparatus 10 on thesecond stage from the top breaks down. In this case, an operator canalso take out the broken down combining unit 5 from the rack by takingout the amplification unit 1 of the power amplification apparatus 10 onthe second stage from the top from the rack. Thus, when exchanging thebroken down combining unit 5, there is no necessity of taking out theplurality of amplification units 1, and thus the combining unit 5 can beeasily exchanged.

When only one power amplification apparatus 10 is used, the one poweramplification apparatus 10 is disposed in a rack (not illustrated). Alsoin the case, when the combining unit 5 breaks down, an operator can alsotake out the broken combining unit 5 from the rack when taking out theamplification unit 1 of the power amplification apparatus 10 from therack, and thus can easily exchange the combining unit 5.

Each input connector 6 is a floating connector. Therefore, even when thearrangement positions of the output connectors 3 of the amplificationunit 1 are somewhat shifted, the output connectors 3 and the inputconnectors 6 corresponding to each other can be simultaneously connectedto each other.

Next, a modification of this embodiment is described.

The description above describes the case where one of the threeamplification circuits 2 contained in one set is the amplificationcircuit 2 a equivalent to the main amplifier and the remaining twoamplification circuits 2 are the amplification circuits 2 b equivalentto the peak amplifier. The two amplification circuits 2 of the threeamplification circuits 2 contained in one set may be the amplificationcircuits 2 a equivalent to the main amplifier and the remaining oneamplification circuit 2 b may be the amplification circuit 2 bequivalent to the peak amplifier.

Moreover, the number of the amplification circuits 2 contained in oneset may be two. Hereinafter, a case where the two amplification circuits2 are set as one set is described. The following description is giventaking a case where the number of the sets of the amplification circuits2 contained in the amplification unit 1 is two as an example in the samemanner as in the embodiment described above but the number of the setsof the amplification circuits 2 contained in the amplification unit 1may be three or more.

FIG. 8 is a schematic view illustrating an example of a poweramplification apparatus when two amplification circuits 2 are set as oneset. The same components as the components illustrated in FIG. 1 to FIG.5 are designated by the same reference numerals as those in FIG. 1 toFIG. 5 and a detailed description therefor is omitted. In the exampleillustrated in FIG. 8, as a result of connecting the output connectors 3and the input connectors 6, each output connector 3 is present in thecorresponding input connector 6.

In the configuration illustrated in FIG. 8, two amplification circuits 2are set as one set, and therefore the number of the output connectors 3and the input connectors 6 each is four, which is different from theconfiguration illustrated in FIG. 1. However, the arrangement of theoutput connectors 3 and the input connectors 6 and the relationshipbetween the side surface 11 on which the output connectors 3 aredisposed of the amplification unit 1 and the side surface 51 on whichthe input connectors 6 are disposed of the combining unit 5 are the sameas those of the above-described embodiment.

Also in the configuration illustrated in FIG. 8, the combining unit 5has a plurality of first combiners 7 and one second combiner 8 in thesame manner as in the case illustrated in FIG. 5. In the exampleillustrated in FIG. 8, two amplification circuits 2 are set as one setand two sets of the amplification circuits 2 are provided, and thereforetwo first combiners 7 are provided in the combining unit 5. Into thefirst combiners 7, RF signals output from the two amplification circuits2 belonging to the set corresponding to the first combiners 7 are input.The first combiners 7 combine the RF signals, and then output the RFsignals after the combination to the second combiner 8.

The first combiner 7 is a combiner usable for RF signals of a specificfrequency band. In other words, the first combiner 7 is a combinerlimited in the frequency band of RF signals which can be combined.Herein, a description is given taking a case where the first combiners 7are all the Doherty combiners as an example.

In the example illustrated in FIG. 8, the set (set of amplificationcircuits 2) corresponding to the first combiner 7 contains twoamplification circuits 2. When the Doherty combiner is used as the firstcombiner 7, one of the two amplification circuits 2 belonging to one setmay be used as the main amplifier and the other one may be used as thepeak amplifier. A bias voltage may be applied to the amplificationcircuit 2 a to be operated as the main amplifier so as to operate inClass AB or Class B. A bias voltage may be applied to the amplificationcircuit 2 b to be operated as the peak amplifier so as to operate inClass C.

As a result, each first combiner 7 combines an RF signal output by theone amplification circuit 2 a which is set so as to operate in Class ABor Class B and an RF signal output by the one amplification circuit 2 bwhich is set so as to operate in Class C.

Processing progress of the power amplification apparatus 10 of theconfiguration of illustrated in FIG. 8 is the same as that of Steps S1to S3 already described above, and thus a description therefor isomitted.

As illustrated in FIG. 8, also when the two amplification circuits 2 areset as one set, the same effects as those in the case where the threeamplification circuits 2 are set as one set are obtained.

Each first combiner 7 may be a Wilkinson combiner. When the Wilkinsoncombiner is used as each first combiner 7, all the amplificationcircuits 2 belonging to each set are set so as to perform an operationin Class AB. For example, as illustrated in FIG. 8, it is supposed thatthe two amplification circuits 2 are set as one set, and then two ormore of the sets of the amplification circuits 2 are provided in theamplification unit 1. Moreover, it is supposed that the Wilkinsoncombiner is provided in the combining unit 5 as the first combiner 7corresponding to each set. In this case, a bias voltage may be appliedto each amplification circuit 2 belonging to each set so as to performan operation in Class AB.

However, the power consumption efficiency in power amplification ishigher in the case of using the Doherty combiner as the first combiner 7than in the case of using the Wilkinson combiner as the first combiner7. Therefore, it is more preferable to use the Doherty combiner as thefirst combiner 7.

Embodiment 2

A second embodiment of the present invention describes a case where oneset of the amplification circuits 2 containing a predetermined number ofthe amplification circuits 2 is provided in the amplification unit 1.FIG. 9 is a schematic view illustrating an example of a poweramplification apparatus of the second embodiment of the presentinvention. The same components as the components described in the firstembodiment are designated by the same reference numerals as those in thefirst embodiment and a detailed description therefor is omitted.

In the present invention, the combiner 7 is provided corresponding tothe set of the amplification circuits 2 provided in the amplificationunit 1. In the second embodiment, one set of the amplification circuits2 containing a predetermined number of the amplification circuits 2 isprovided in the amplification unit 1, and therefore the combining unit 5has one combiner 7 corresponding to the one set. The number of thecombiners 7 provided in the combining unit 5 is one, and therefore thesecond combiner 8 (refer to FIG. 5) is not provided in the combiningunit 5 in the second embodiment. In general, the return losscharacteristics as viewed from the output side of an FET are not goodand total reflection occurs. Therefore, in order to improve the returnloss characteristics as viewed from the output side, the combining unit5 may have an isolator 15 on the latter stage of the one combiner 7.

In the example illustrated in FIG. 9, the amplification unit 1 has oneset containing three amplification circuits 2. Therefore, the number ofthe output connectors 3 provided in the amplification unit 1 and thenumber of the input connectors 6 provided in the combining unit 5 eachare three. However, the arrangement of the output connectors 3 and theinput connectors 6 and the relationship between the side surface 11 onwhich the output connectors 3 are disposed of the amplification unit 1and the side surface 51 on which the input connectors 6 are disposed ofthe combining unit 5 are the same as those of the first embodiment.

The combiner 7 is a Doherty combiner, for example. When the Dohertycombiner is used as the combiner 7, one of the three amplificationcircuits 2 contained in the set of the amplification circuits 2 may beused as the main amplifier and the remaining two amplification circuits2 may be used as the peak amplifier. A bias voltage may be applied tothe amplification circuit 2 a to be operated as the main amplifier so asto operate in Class AB or Class B. A bias voltage may be applied to theamplification circuits 2 b to be operated as the peak amplifier so as tooperate in Class C.

As a result, the combiner 7 combines an RF signal output by the oneamplification circuit 2 a which is set so as to operate in Class AB orClass B and RF signals output by the two amplification circuits 2 bwhich are set so as to operate in Class C. The combiner 7 outputs thesignal after the combination from the output end 9 through the isolator15. The output end 9 is provided on the side surface opposite to theside surface 51 on which the input connectors 6 are disposed in thecombining unit 5 in the same manner as in the first embodiment. The RFsignal output from the output end 9 is transmitted to a device on thelatter stage of the power amplification apparatus 10.

FIG. 10 is a schematic view illustrating a state where the amplificationunit 1 and the combining unit 5 are connected to each other in thesecond embodiment of the present invention. By simultaneously connectingthe output connectors 3 and the input connectors 6 corresponding to eachother in the same manner as in the first embodiment, the amplificationunit 1 and the combining unit 5 are brought into a connection state. Inthe example illustrated in FIG. 10, as a result of connecting the outputconnectors 3 and the input connectors 6, each output connector 3 ispresent in the corresponding input connector 6.

Next, processing progress of the power amplification apparatus 10 isdescribed. FIG. 11 is a flow chart illustrating an example of theprocessing progress of the power amplification apparatus 10 of thesecond embodiment of the present invention. As illustrated in FIG. 10,the amplification unit 1 and the combining unit 5 are in the connectionstate and the power amplification apparatus 10 is in an operation state.

An RF signal is input into the one amplification circuit 2 a and the twoamplification circuits 2 b forming a set. The frequency band of the RFsignal is set in the frequency band for which a broadcastingorganization using the power amplification apparatus 10 has obtainedapproval. The amplification circuit 2 a operates as the main amplifier,the amplification circuits 2 b operate as the peak amplifier, and theamplification circuits 2 a and 2 b output RF signals after poweramplification to the combiner 7 (Step S11). In Step S11, eachamplification circuit 2 outputs the RF signal after power amplificationto the combiner 7 through the output connectors 3 and the inputconnectors 6 connected to each other.

The combiner 7 combines RF signals output from the one amplificationcircuit 2 a and the two amplification circuits 2 b, and then outputs theRF signal after the combination from the output end 9 through theisolator 15. The RF signal output from the output end 9 is transmittedto a device on the latter stage of the power amplification apparatus 10.

Also in the second embodiment, the same effects as those of the firstembodiment are obtained.

Moreover, various modifications described in the first embodiment arealso applied to the second embodiment.

For example, two amplification circuits 2 of the three amplificationcircuits 2 contained in one set may be the amplification circuits 2 aequivalent to the main amplifier and the remaining one amplificationcircuit 2 may be the amplification circuit 2 b equivalent to the peakamplifier.

For example, a configuration in which the set of the amplificationcircuits 2 contains two amplification circuits may be acceptable. Whenthe combiner 7 is the Doherty combiner, one amplification circuit 2 ofthe two amplification circuits 2 may be used as the main amplifier andthe other amplification circuit 2 may be used as the peak amplifier. Abias voltage may be applied to the amplification circuit 2 a to beoperated as the main amplifier so as to operate in Class AB or B. A biasvoltage may be applied to the amplification circuit 2 b to be operatedas the peak amplifier so as to operate in Class C.

For example, the combiner 7 may be a Wilkinson combiner. For example, itis supposed that one set of the amplification circuits 2 containing twoamplification circuits 2 is provided in the amplification unit 1.Moreover, it is supposed that the Wilkinson combiner is provided as theone combiner 7 corresponding to the set in the combining unit 5. In thiscase, a bias voltage may be applied to the two amplification circuits 2so as to operate in Class AB.

In the first embodiment and the second embodiment, the output connectors3 arranged in the transverse direction may be disposed in a plurality ofstages on the side surface 11 on which the output connectors 3 aredisposed of the amplification unit 1. FIG. 12 is a view illustrating anexample of the amplification unit 1 in which the output connectors 3arranged in the transverse direction are disposed in two stages. In theexample illustrated in FIG. 12, six output connectors 3 arranged in thetransverse direction are disposed in two stages on the side surface 11of the amplification unit 1. The number of the output connectors 3arranged in each stage is common. Moreover, the amplification unit 1 isprovided with the amplification circuits 2 (not illustrated in FIG. 12)corresponding to the six output connectors 3 on the upper stage arrangedin the transverse direction and the amplification circuits 2 (notillustrated in FIG. 12) corresponding to the six output connectors 3 onthe lower stage arranged in the transverse direction. In this case, thepower amplification apparatus 10 may have two combining units 5 havingthe six input connectors 6 corresponding to the six output connectors 3,and then one combining unit 5 may be connected to the six outputconnectors 3 on the upper stage arranged in the transverse direction andthe other combining unit 5 may be connected to the six output connectors3 on the upper stage arranged in the transverse direction. At this time,the two combining units 5 may be disposed in one chassis.

Embodiment 3

Next, a television signal transmission system is described as a thirdembodiment of the present invention. FIG. 13 is a block diagramillustrating an example of the configuration of the television signaltransmission system of the third embodiment of the present invention. Atelevision signal transmission system 20 illustrated in FIG. 13 has twoor more of the power amplification apparatuses 10 each containing theamplification unit 1 and the combining unit 5. The power amplificationapparatus 10 may be the power amplification apparatus 10 described inthe first embodiment or the modification thereof or may be the poweramplification apparatus 10 described in the second embodiment or themodification thereof. However, the power amplification apparatuses 10have the same configuration. The following description is given taking acase where the television signal transmission system 20 has two or moreof the power amplification apparatuses 10 described in the firstembodiment as an example.

In a rack (not illustrated), the plurality of power amplificationapparatuses 10 is disposed in a plurality of stages in the verticaldirection. In FIG. 13, the amplification units 1 and the combining units5 are connected to each other and the output connectors 3 are present inthe corresponding input connectors 6. FIG. 13 does not illustrate theamplification circuit 2 in the amplification unit 1 and the firstcombiner 7 and the second combiner 8 in the combining unit 5.

The television signal transmission system 20 further has an exciter 21,a distributor 22, a power combiner 23, a filter unit 24, an antenna 25,and a controller 26.

The exciter 21 is connected to the distributor 22. The exciter 21generates an RF signal to be transmitted as a television signal, andthen outputs the resultant RF signal to the distributor 22. Thefrequency band of the RF signal is a frequency band for which abroadcasting organization using the television signal transmissionsystem 20 has obtained approval.

The distributor 22 is connected to the amplification unit 1 of eachpower amplification apparatus 10. Each amplification unit 1 and thedistributor 22 are attachable/detachable. For example, a configurationin which each output connector of the branching filter 22 and each inputconnector of each power amplification apparatus 10 (more specificallyeach amplification unit 1) are connected to each other with a coaxialcable may be acceptable.

The distributor 22 distributes an RF signal output from the exciter 21to each amplification circuit 2 provided in the amplification unit 1 ofeach power amplification apparatus 10.

The power combiner 23 is connected to the combining unit 5 of each poweramplification apparatus 10. Each combining unit 5 and the power combiner23 are attachable/detachable.

The power combiner 23 performs power combination of an RF signal outputfrom the combining unit 5 of each power amplification apparatus 10, andthen outputs the resultant signal through the filter unit 24 and theantenna 25.

The filter unit 24 is a bandpass filter passing only RF signals of thefrequency band for which a broadcasting organization using thetelevision signal transmission system 20 has obtained approval.

The controller 26 switches ON/OFF of the operation of the exciter 21 ormonitors the state of each amplification unit 1.

Next, processing progress of the television signal transmission system20 is described. FIG. 14 is a flow chart illustrating an example of theprocessing progress of the television signal transmission system 20.

The exciter 21 generates an RF signal, and then outputs the RF signal tothe distributor 22 (Step S21).

Next, the distributor 22 distributes the RF signal output from theexciter 21 to each amplification circuit 2 (not illustrated in FIG. 13)in each amplification unit 1 (Step S22).

Operations of the power amplification apparatus 10 after Step S22 arethe same as the already described operations (Steps 1 to 3 in the firstembodiment in this example), and thus a description therefor is omittedherein.

After Step S3, the power combiner 23 performs power combination of theRF signals output from the output end 9 by each combining unit 5, andthen transmits the resultant RF signal through the filter unit 24 andthe antenna 25 (Step S23).

The television signal transmission system 20 of this embodiment has thepower amplification apparatus 10 described in the first embodiment orthe modification thereof or the power amplification apparatus 10described in the second embodiment or the modification thereof.Therefore, also in this embodiment, the same effects as those of thefirst embodiment or the second embodiment are obtained.

The television signal transmission system 20 may be configured so as tohave one power amplification apparatus 10. FIG. 15 is a block diagramillustrating an example of a television signal transmission systemhaving one power amplification apparatus 10. The same components as thecomponents illustrated in FIG. 13 are designated by the same referencenumerals as those in FIG. 13 and a description therefor is omitted.

When the number of the power amplification apparatus 10 provided in thetelevision signal transmission system 20 is one, the distributor 22 andthe power combiner 23 may not be provided (refer to FIG. 15). This isbecause there is no necessity of performing power combination of RFsignals output from two or more of the combining units 5.

In the configuration illustrated in FIG. 15, the combining unit 5 andthe filter unit 24 are attachable/detachable. For example, aconfiguration in which the output connector (the output end 9 describedabove) of the combining unit 5 and the input connector of the filterunit 24 are connected to each other with a coaxial feeder may beacceptable. The amplification unit 1 and the exciter 21 areattachable/detachable. For example, a configuration in which the outputconnector of the exciter 21 and the input connector of the amplificationunit 1 are connected to each other with a coaxial cable may beacceptable.

In the configuration illustrated in FIG. 15, the combining unit 5 of thepower amplification apparatus 10 transmits an RF signal after thecombination through the filter unit 24 and the antenna 25.

Next, the outline of the present invention is described. FIG. 16 is ablock diagram illustrating the outline of the power amplificationapparatus of the present invention. The power amplification apparatus 10of the present invention has the amplification unit 1 containing atleast one set containing a predetermined number of amplificationcircuits 2 amplifying the power of an RF signal and the combining unit 5containing the combiner 7 provided corresponding to the set andcombining RF signals output by the amplification circuits 2 belonging tothe corresponding set, and then outputting the resultant RF signal.

The amplification unit 1 has the output connectors 3 for outputting anRF signal output by the amplification circuit 2 for each amplificationcircuit. The output connectors 3 are disposed so as to be arranged inthe horizontal direction.

The combining unit 5 has the input connector 6 into which an RF signaloutput from the output connector 3 of the amplification unit 1 is inputfor each output connector 3. The input connectors are disposed so as tobe arranged in the horizontal direction.

The amplification unit 1 and the combining unit 5 areattachable/detachable through the output connectors 3 and the inputconnectors 6.

The surface on which the input connectors are provided of the combiningunit 5 is set within the dimension of the surface on which the outputconnectors are provided of the amplification unit 1.

Such a configuration enables the separation of the component(amplification unit 1) for power amplification of RF signals and thecomponent (combining unit 5) for combination of RF signals and easyexchange of the component (combining unit 5) for combination of RFsignals.

The embodiments described above may be also described as in thefollowing supplementary notes but is not limited thereto.

(Supplementary note 1) A power amplification apparatus according to thepresent invention has an amplification unit containing at least one setcontaining a predetermined number of amplification circuits amplifyingthe power of an RF (Radio Frequency) signal and a combining unitcontaining a combiner provided corresponding to the set and combining RFsignals output by the amplification circuits belonging to thecorresponding set, and then outputting the resultant RF signal, in whichthe amplification unit has an output connector for outputting the RFsignal output by the amplification circuit for each amplificationcircuit, the output connectors are arranged in the horizontal direction,the combining unit has an input connector into which the RF signaloutput from the output connector of the amplification unit is input foreach output connector, the input connectors are arranged in thehorizontal direction, the amplification unit and the combining unit areattachable/detachable through the output connectors and the inputconnectors, and the surface on which the input connectors are providedof the combining unit is set within the dimension of the surface onwhich the output connectors are provided of the amplification unit.(Supplementary note 2) In the power amplification apparatus described inSupplementary note 1, the amplification unit contains two or more of thesets containing a predetermined number of the amplification circuits,the combining unit contains two or more of the combiners combining RFsignals output by the amplification circuits, and then outputting theresultant RF signal and contains a second combiner combining the RFsignals output by the combiners.(Supplementary note 3) In the power amplification apparatus described inSupplementary note 1 or 2, each input connector is a floating connecter.(Supplementary note 4) In the power amplification apparatus described inany one of Supplementary notes 1 to 3, each output connector outputs anRF signal output by a corresponding amplification circuit as it is.(Supplementary note 5) In the power amplification apparatus described inany one of Supplementary notes 1 to 4, each amplification circuit is anFET (Field Effect Transistor).(Supplementary note 6) In the power amplification apparatus described inany one of Supplementary notes 1 to 5, the combiner in the combiningunit combining RF signals output by the amplification circuits, and thenoutputting the resultant RF signal is a Doherty combiner.(Supplementary note 7) In the power amplification apparatus described inany one of Supplementary notes 1 to 6, each set of the amplificationcircuits contains three amplification circuits, one amplificationcircuit of the three amplification circuits is an amplification circuitwhich is set so as to operate in Class AB or Class B, the remaining twoamplification circuits are amplification circuits which are set so as tooperate in Class C, and the combiner in the combining unit combining RFsignals output by the amplification circuits, and then outputting theresultant RF signal is the Doherty combiner.(Supplementary note 8) In the power amplification apparatus described inany one of Supplementary notes 1 to 6, each set of the amplificationcircuits contains two amplification circuits, one amplification circuitof the two amplification circuits is an amplification circuit which isset so as to operate in Class AB or Class B, the remaining oneamplification circuit is an amplification circuit which is set so as tooperate in Class C, and the combiner in the combining unit combining RFsignals output by the amplification circuits, and then outputting theresultant RF signal is the Doherty combiner.(Supplementary note 9) A television signal transmission system has thepower amplification apparatus described in any one of Supplementarynotes 1 to 8.

INDUSTRIAL APPLICABILITY

The present invention is suitably applied to a television signaltransmission system or a power amplification apparatus provided in thetelevision signal transmission system.

REFERENCE SIGNS LIST

-   -   1 amplification unit    -   2 amplification circuit    -   3 output connector    -   5 combining unit    -   6 input connector    -   7 combiner (first combiner)    -   8 second combiner    -   10 power amplification apparatus    -   20 television signal transmission system    -   21 exciter    -   22 distributor    -   23 power combiner    -   24 filter unit    -   25 antenna    -   26 controller

1. A power amplification apparatus provided in a television signaltransmission system, the power amplification apparatus comprising: anamplification unit, containing two or more sets containing a pluralityof amplification circuits, that amplifies power of a radio frequency(RF) signal; and a combining unit, containing two or more combinerscorresponding to the two or more sets, that combines RF signals outputby the amplification circuits, and outputs a resultant RF signal,wherein; the amplification unit and the combining unit have two or moreconnectors which are arranged transversely, the amplification unit andthe combining unit are attachable/detachable, a housing of theamplifying unit and a housing of the combining unit are separatehousings, and the housing of the amplifying unit and the housing of thecombining unit have one-to-one correspondence when the amplifying unitis attached to the combining unit.
 2. The power amplification apparatusaccording to claim 1, wherein the combining unit, containing a secondcombiner, combines RF signals output by the two or more combiners, andthen outputs the resultant RF signal.
 3. The power amplificationapparatus according to claim 1, wherein each amplification circuit is afield effect transistor (FET).
 4. The power amplification apparatusaccording to claim 1, wherein the two or more combiners in the combiningunit are Doherty combiners.
 5. The power amplification apparatusaccording to claim 1, wherein each set of the amplification circuitscontains three amplification circuits, wherein one amplification circuitof the three amplification circuits is an amplification circuit which isset so as to operate in Class AB or Class B, and two amplificationcircuits are amplification circuits which are set so as to operate inClass C, and the two or more combiners in the combining unit are Dohertycombiners.
 6. The power amplification apparatus according to claim 1,wherein each set of the amplification circuits contains twoamplification circuits, wherein one amplification circuit of the twoamplification circuits is an amplification circuit which is set so as tooperate in Class AB or Class B, and the other is an amplificationcircuit which is set so as to operate in Class C, and the two or morecombiners in the combining unit are Doherty combiners.